A squeak or clunk sound from the rear leaf springs may be heard on some 2015-2021 Silverado 2500HD/3500HD and Sierra 2500HD/3500HD models. The sound may be caused by the spring insert interacting with the leaf spring. Keep in mind that some noise is a normal characteristic of leaf spring suspensions when travelling over rough roads or bumps.
To help reduce excessive leaf spring noise, a new insert with a graining pattern is available. (Fig. 23) Replace the rear leaf spring inserts using a plastic trim tool or plastic wedge in between the leaf springs.
Fig. 23
TIP: New spring tip inserts have a break-in period of up to 1,000 miles (1,610 km), so some noise can be expected after the new inserts are installed. Also, these inserts are designed to work without any lubricant.
Follow the service procedure in the appropropriate Service Information to install the new inserts. The bolt that secures the clip to the spring alignment bracket must be removed to relieve spring tension.
Do not chip the painted coating on the springs when performing the repair. A rag should be placed in the area where contact with the spring may occur. (Fig. 24, #2)
Use a plastic trim tool, plastic wedge or equivalent to separate the rear springs. (Fig. 24, #3)
Fig. 24
Clean any dirt or grease from between the leaf spring using a rag and degreaser before replacing the inserts for the left and right side springs. (Fig. 25)
Fig. 25
There is no need to adhere or modify the inserts as removal of the spring clip allows for proper access.
For additional information and part numbers, refer to Bulletin #21-NA-138.
– Thanks to Kevin Minor and Scott Lewiston
